1. Field of the Invention
The present invention relates to an electronic clutch control apparatus for a vehicle. More particularly, the present invention related to an electronic clutch control apparatus including an actuator for driving a clutch assembly, an operation amount sensor for sensing an operation amount of a clutch lever, an electronic control unit for controlling operation of the actuator based on a detected operation amount of the clutch lever, and a feedback unit for applying an operation reaction force to the clutch lever.
2. Description of the Background Art
There is a known system for assisting a clutch operating force, for example, the system disclosed in the Japanese Patent Laid-open No. 2008-275084, wherein a driving force of an actuator can be transmitted to an operation force transmitting member, capable of transmitting an operating force, which has been applied to a clutch lever, to a clutch assembly.
Also known from the other Japanese Patent Laid-open No. 2003-239772 is an electronic throttle valve control device, in which an operation amount of a throttle lever is detected by a throttle lever position sensor, and the operation of an actuator for driving a throttle valve is controlled according to the operation amount detected by the throttle lever position sensor.
By applying the system disclosed in the Japanese Patent Laid-open No. 2003-239772 for operating the clutch assembly for controlling the operation of the actuator for driving the clutch assembly according the operation amount of the clutch lever, it is not necessary to route a hydraulic system and wires provided between the clutch lever and the clutch assembly.
Accordingly, the number of parts can be reduced and the flexibility of vehicle body layout can be improved. Furthermore, the operating force applied to the clutch lever can be reduced and the assisting device disclosed in the Japanese Patent Laid-open No. 2008-275084 can therefore be eliminated.
For controlling operation of the actuator for driving the clutch assembly according to the operation amount of the clutch lever, a feedback unit for applying an operation reaction force to the clutch lever is required. In the prior art apparatus, when an operation force applied to the clutch lever is transmitted to the clutch assembly by oil pressure or wire, there occurs play in a hydraulic system, due to the deformation of a hose or the like, or play in a wire system due to the extension of a wire or the like until a reaction force of a clutch spring is produced after starting the operation of the clutch lever.
The relation between the operation amount of the clutch lever and the operation load on the clutch lever changes among an initial stage where the above-mentioned play is occurring, the next stage where the clutch assembly is engaged or disengaged against the elastic force of the clutch spring, and the subsequent stage after engagement or disengagement of the clutch assembly.
If a feedback unit is simply configured such that the reaction force is proportionally increased with an increase in force applied to the clutch lever, an operator in the vehicle is given an operation feel different from feel experienced by operating the conventional clutch actuation systems.
It is accordingly one of the objects of the present invention to provide an electronic clutch control apparatus having an actuator for driving a clutch assembly which can make the operation feel of a clutch lever similar to an operation feel experienced during operation of a conventional clutch lever.